It says a lot about Theresa May’s handling of Brexit that the principle of a “meaningful” vote for parliament on the final deal has been settled, but only by deferring agreement on the meaning of “meaningful”.

The prime minister has promised to satisfy Tory rebel demands that MPs be consulted on future steps in the event that the deal is voted down. This is significant because parliament’s binary right to approve or reject May’s Brexit terms (conceded last year) had set up a game of chicken. The government could tell parliament that the options were May’s deal or no deal at all; capitulation or chaos.

Tory moderates and opposition parties want a more diverse menu. May appears to be offering one. What exactly she is putting on the menu is unclear. The compromise was cooked up in fevered discussion on the margins of a Commons debate and it is easy to get lost in the procedural labyrinth that has led to this point.

But, viewed from a step back, the political dynamic has three forces.

1. Soft Brexiters and unbowed remainers want a safety net to minimise the hazard of no deal.

2. May resists anything that limits her room for manoeuvre.

3. Hard Brexiters dread the creation of legislative trapdoors through which pro-EU feeling might sneak in and kidnap their dream.

Parliamentary arithmetic favours the soft Brexiters. That is the salient storyline in Tuesday’s Commons theatre. If May tries to renege on the substance of what was agreed with the moderates, she will incite a bigger, angrier rebellion. There is plenty of Brexit legislation to which that fury might attach itself. Besides, May is not a Europhobe fanatic. She wants a deal. She also wants to avoid ripping the Conservatives apart. Those things are not easily combined, but her method has proved surprisingly effective. It is sometimes compared by ministers to the “rope-a-dope” – the boxing tactic famously used by Muhammad Ali in his 1974 bout with George Foreman in Zaire. Ali leant into the ropes, rolling with Foreman’s punches, using sheer stamina to drain his opponent of energy before launching a lethal counter-attack.

May is no Ali. She is not The Greatest. She neither floats like a butterfly, nor stings much like a bee. But the rope-a-dope is working against the hard Brexiters. They throw their fists wildly, threatening to resign or to unseat their leader, but May is still standing and her Brexit agenda is softening daily.

How long can this go on? The hard Brexiters feel a creeping sense of betrayal but their options are limited. There is really only one: the nuclear option of challenging May and hoping to replace her with one of their own. But that is high risk. She could survive. She could be replaced by a more moderate leader. The government could collapse, triggering a sequence of falling constitutional dominoes that ends with Labour taking power.

And it isn’t obvious that the Brexit ultras would want to be in control of the process now. Then they would have to negotiate, to own the compromises and explain the disappointments. They would no longer have the luxury of crying betrayal from the sidelines, which is all they really know how to do. But they also have limits and pride. There is surely a point at which the compromises get too big and too bitter to swallow.

There are some Tory MPs whose attachment to the hardest-possible Brexit is greater than their attachment to anything else. They say they would sooner detonate than dilute. They would bring May’s temple down before worshipping at an altar facing Brussels, even if that means making Jeremy Corbyn prime minister. Some of them are bluffing, but how many? Some pro-Brexit Tory MPs feel they are being sold out but others are fed up with the whole business and, mindful that their constituents aren’t fussed about the detail, take the view that any Brexit is better than no Brexit.

May’s gamble is that the number of obedient Tory congregants will grow and the number of temple-trashing ultras will shrink. It is a reasonable bet, but not a safe one. That is the meaning of her compromise on the “meaningful vote”. It leans towards a softer deal, which pushes the hardest leavers towards their breaking point. It makes the prospect of no deal and chaos less likely, but also, to the most extreme Brexiteers, more enticing.